Low smoke polyolefin jacket composition for electrical wire

Abstract

A cross-linked polyolefin jacketing and/or insulating composition for use on wire and cable having superior resistance to the propagation of flame, a low smoke emission level and low emission of toxic byproducts when subjected to heat or flame, as well as low moisture absorption characteristics and high resistance to weathering, oils and chemicals, which comprises a polyethylene-vinyl acetate copolymer, magnesium silicate, and alumina hydrate in major proportions, and, in minor proportions, carbon black, polymerized 1,2-dihydro 2,2,4-trimethyl quinoline, stearic acid, vinyl-tris (β-methoxethoxy)silane, triallyl cyanurate, and di-cumyl peroxide in anhydrous aluminum silicate.

We claim: 
     
       1. A cross-linked polyolefin jacketing composition for use on wire and cable having superior resistance to the propagation of flame, a low smoke emission level and low emission of toxic byproducts when subjected to heat or flame, as well as low moisture absorption characteristics and high resistance to weathering, oils and chemicals, which consists essentially of a polyethylene-vinyl acetate copolymer, magnesium silicate, and alumina hydrate in major proportions, and, in minor proportions, carbon black, polymerized 1,2-dihydro 2,2,4 trimethyl quinoline, stearic acid, vinyl-tris (β-methoxethoxy)silane, triallyl cyanurate, and di-cumyl peroxide in anhydrous aluminum silicate. 
     
     
       2. A cross-linked polyolefin jacketing composition for use on wire and cable according to claim 1 which consists essentially of about 100 phr of a polyethylene-vinyl acetate copolymer, about 30 phr magnesium silicate and about 150 phr alumina hydrate, in combination with about 2 phr carbon black, about 1.5 phr polymerized 1,2-dihydro 2,2,4 trimethyl quinoline, about 1.0 phr stearic acid, about 2.0 phr vinyl-tris (β-methoxethoxy)silane, about 1.3 phr triallyl cyanurate and 4.0 phr di-cumyl peroxide in anhydrous aluminum silicate. 
     
     
       3. A jacketed wire or cable wherein the jacketing consists essentially of of a polyethylene-vinyl acetate copolymer, magnesium silicate, and alumina hydrate in major proportions, and, in minor proportions, carbon black, polymerixed 1,2-dihydro 2,2,4 trimethyl quinoline, stearic acid, vinyl-tris (β-methoxethoxy)silane, triallyl cyanurate, and di-cumyl peroxide in anhydrous aluminum silicate. 
     
     
       4. A jacketed wire or cable according to claim 3 wherein the jacketing consists essentially of of about 100 phr of a polyethylene-vinyl acetate copolymer, about 30 phr magnesium silicate and about 150 phr alumina hydrate, in combination with about 2 phr carbon black, about 1.5 phr polymerized 1,2-dihydro 2,2,4 trimethyl quinoline, about 1.0 phr stearic acid, about 2.0 phr vinyl-tris (β-methoxethoxy)silane, about 1.3 phr triallyl cyanurate and 4.0 phr di-cumyl peroxide in anhydrous aluminum silicate. 
     
     
       5. A cross-linked polyolefin insulating composition for use on wire and cable having superior resistance to the propagation of flame, a low smoke emission level and low emission of toxic byproducts when subjected to heat or flame, as well as low moisture absorption characteristics and high resistance to weathering, oils and chemicals, which consists essentially of a polyethylene-vinyl acetate copolymer, magnesium silicate, and alumina hydrate in major proportions, and, in minor proportions, carbon black, polymerized 1,2-dihydro 2,2,4 trimethyl quinoline, stearic acid, vinyl-tris (β-methoxethoxy)silane, triallyl cyanurate, and di-cumyl peroxide in anhydrous aluminum silicate. 
     
     
       6. A cross-linked polyolefin insulating composition for use on wire and cable according to claim 5 which consists essentially of about 100 phr of a polyethylene-vinyl acetate copolymer, about 30 phr magnesium silicate and about 150 phr alumina hydrate, in combination with about 2 phr carbon black, about 1.5 phr polymerized 1,2-dihydro 2,2,4 trimethyl quinoline, about 1.0 phr stearic acid, about 2.0 phr vinyl-tris (β-methoxethoxy)silane, about 1.3 phr triallyl cyanurate and 4.0 phr di-cumyl peroxide in anhydrous aluminum silicate. 
     
     
       7. An insulated wire or cable wherein the insulation consists essentially of of polyethylene-vinyl acetate copolymer, magnesium silicate, and alumina hydrate in major proportions, and, in minor proportions, carbon black, polymerized 1,2-dihydro 2,2,4 trimethyl quinoline, stearic acid, vinyl tris (β-methoxethoxy)silane, triallyl cyanurate, and di-cumyl peroxide in anhydrous aluminum silicate. 
     
     
       8. An insulated wire or cable according to claim 7 where in the insulation consists essentially of of about 100 phr of a polyethylene-vinyl acetate copolymer, about 30 phr magnesium silicate and about 150 phr alumina hydrate, in combination with about 2 phr carbon black, about 1.5 phr polymerized 1,2-dihydro 2,2,4 trimethyl quinoline, about 1.0 phr stearic acid, about 2.0 phr vinyl-tris (β-methoxethoxy)silane, about 1.3 phr triallyl cyanurate and 4.0 phr di-cumyl peroxide in anhydrous aluminum silicate.